53. Use 24-hour and 2-hour Appointment Reminders

Status

Accepted for the MVP working model; exact opt-out, quiet hours, and provider failure behavior remain open.

Context

A single reminder may be missed; too many reminders add noise. The practice uses Asia/Jakarta operational time and needs predictable behavior when an Appointment is rescheduled or cancelled.

Decision

Schedule two transactional email reminders by default:

• 24 hours before Appointment start;
• 2 hours before Appointment start.

Offsets are configurable by Admin within the notification policy. ReminderSchedule computes them from the Appointment's canonical instant and renders Asia/Jakarta local date/time. Reschedule/cancellation/terminal outcome cancels stale reminders and creates new ones where applicable. Each send has an idempotency key so retries cannot duplicate a reminder.

Consequences

Positive:

• predictable minimal reminder cadence;
• local-time copy matches operational schedule;
• reschedule behavior is explicit;
• duplicate delivery is preventable.

Costs and constraints:

• appointments created inside an offset may skip one reminder;
• scheduler clock/timezone tests are required;
• email failure/manual support path remains necessary;
• quiet hours and client preferences need policy.

Open follow-up

Define package-expiry offsets, notification opt-out/mandatory rules, quiet hours, and late-created appointment behavior.